ADI's six product solutions pave the way for the evolution of 48V/12V dual-battery automotive systems

At the recently held "2018 Third Automotive 48V System Technology Forum", Lorry Liang, Marketing Director of ADI's Power Products in China, demonstrated ADI's products that can be used in automotive 48V systems to participating automakers and component suppliers, including:

ADI Power Products China Marketing Director Liang Zaixin (Lorry) is giving a speech

The LTC3871 is a 100V/30V bidirectional, 2-phase synchronous buck or boost controller that provides bidirectional DC/DC control and battery charging between 12V and 48V automotive batteries.

The device brings new levels of performance, control and simplified circuitry to 48V/12V dual-battery DC/DC automotive systems by allowing the same external power components to be used for both buck and boost purposes. The device can operate in buck mode (from 48V bus to 12V bus) or boost mode (from 12V to 48V) as required. Up to 12 phases can be paralleled to meet the needs of high current and high power (3KW-10KW) applications.

When starting the car or when additional power is needed, the LTC3871 allows both batteries to provide energy to the same load simultaneously. The 48V battery will play a central role in increasing available energy while also reducing wiring harness weight and losses. This additional energy paves the way for new technologies that can make the car safer and more efficient while reducing its CO2 emissions.

LT8708/-1 is ADI's latest 98% efficient bidirectional buck-boost controller for 12V-12V redundant battery systems for autonomous vehicles, which can operate between two batteries with the same voltage. It operates with an input voltage that can be higher, lower or equal to the output voltage, making it very suitable for two batteries of 12V, 24V or 48V each, which are common in electric and hybrid vehicles.

The LT8708/-1 operates from a 2.8V to 80V input voltage range with a single inductor and can generate an output voltage from 1.3V to 80V, providing up to several kW of power, depending on the selection of external components and the number of phases. It simplifies bidirectional power conversion in battery/capacitor backup systems that require regulation of VOUT, VIN and/or IOUT, IIN in the forward or reverse direction. The device's six independent regulation modes enable it to be used in a wide range of applications.

At this point, someone may raise their hand and ask, "Both LT8708 and LTC3871 are powerful. Which one is more suitable for a 48V/12V dual system?"

Share a "PK" picture that Lorry showed you on the spot. Which one to use depends on your system requirements~

The LTC4368 circuit protection controller ensures safe voltage and current levels for 2.5V to 60V electronic circuits in battery-powered automotive, industrial and portable systems. The LTC4368 replaces fuses, transient voltage suppressors and discrete circuits to achieve a compact and comprehensive solution for protecting electronic circuits from harmful overcurrents and overvoltage, undervoltage and reverse voltage conditions. The LTC4368 controls back-to-back N-channel MOSFETs to provide a low-loss current path during normal operation and shuts them off when a forward or reverse overcurrent fault occurs.

The LTC4368 is available in two versions. The LTC4368-1 circuit breaker provides symmetrical forward and reverse current thresholds to protect the battery from excessive charge and discharge currents. The LTC4368-2 circuit breaker trips when reverse current is detected to prevent backfeed and maintain the output.

For body control circuits that need to work in both 12V and 48V systems, diodes may be needed at certain times to implement reverse protection or combined backup power supply functions. Although the current does not need to be as large as that of the motor, the heat caused by the loss on the diode cannot be ignored.

The LTC4415, a monolithic dual 4A PowerPath ideal diode, is an ideal choice for applications that require an ideal diode-ORing function for load sharing or automatic switching between two input supplies. The LTC4415's ultra-low 15mV forward voltage is significantly lower than that of a Schottky diode, extending battery run time and operating voltage range while ensuring no oscillation when switching between supplies. The low 50mΩ on-resistance reduces power dissipation and heat.

The LTC4357 monolithic high voltage ideal diode-OR controller provides a lower loss path compared to Schottky diodes, resulting in a more efficient solution in high power applications while saving valuable board area by eliminating the need for a heat sink.

The LT4320 ideal diode bridge controller replaces four diodes in a full-wave bridge rectifier with low-loss N-channel MOSFETs to significantly reduce power dissipation and increase available voltage. The improved power efficiency eliminates the need for bulky heat sinks, thus reducing the size of the power supply. Additional margin is provided by eliminating the two diode drops inherent in the diode bridge, which is particularly suitable for low-voltage applications. Compared with traditional alternatives, the MOSFET bridge enables a rectifier design with high space utilization and power efficiency.

EMI is generally caused by the power supply. To solve this problem, ADI's Silent Switcher technology has been deeply optimized for noise and interference indicators. Buck regulators using the Silent Switcher architecture can reduce the EMI of today's advanced switching regulators by more than 20dB while improving conversion efficiency. A 10-fold improvement in EMI can be achieved in the frequency range above 30MHz without sacrificing minimum on and off times or efficiency with the same circuit board area. The above goals are achieved without the use of special components or shielding, marking a major breakthrough in the field of switching regulator design.

The LT8609S, a switching regulator with Silent Switcher® 2 architecture, uses two internal input capacitors as well as internal BST and INTVCC capacitors to minimize the hot loop area. The LT8609S design significantly reduces EMI/EMC emissions by providing very well controlled switching edges. This improved EMI/EMC performance is insensitive to board layout, simplifying design and reducing risk, even when using a two-layer PC board.

When automotive electronic devices fail, operate incorrectly, or short-circuit, surge current is easily generated. Surge current can cause wires and contacts to generate high temperatures, burn insulation, cause short circuits, and even cause fires. Therefore, surge limiters and OV/OC protection controllers are indispensable in automotive applications.

Analog Devices' ultra-low quiescent current (IQ) surge stopper, the LTC4380, provides compact overvoltage and overcurrent protection for 4V to 72V electronic components that are always on in automotive, industrial and avionics systems. The LTC4380 replaces the traditional shunt circuit consisting of large and bulky inductors, capacitors, transient voltage suppressors (TVS) and fuses with a simple IC and series N-channel MOSFET solution, saving board space and achieving continuous operation during transient voltage or current surges.

During input voltage surges (e.g., automotive load dump), the LTC4380 reduces the excessive voltage across the external MOSFET while clamping its gate, thereby limiting the output to a safe voltage. This allows the use of downstream electronic components with lower voltage ratings, saving cost.

The new device LTC4380-2 further improves the safety of such devices. It can withstand -28V negative voltage, making the device's own reverse polarity protection a standard feature. The power supply end can withstand a 1ms instantaneous high voltage of 600V, further improving system safety.

Lorry, that’s all the sincere and useful information I’m sharing. The above products are all from ADI’s Power by Linear .

Power by Linear's high-performance analog ICs provide efficient solutions for power management and conversion applications in the automotive, telecommunications, industrial, healthcare, computing and high-end consumer electronics markets. To learn more about Power by Linear's products, please click "Read the original article"

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